1. Field of the Invention
The present invention relates to digital wireless communication systems. More particularly, the invention relates to a system and method for repeatedly and efficiently performing a wireless communication channel survey to determine whether comparable communications devices exist, which frequencies are in use and the identities of the comparable communications devices.
2. Background of the Related Art
Existing digital wireless communication systems communicate on a single RF channel at any one time, as exemplified by access points and clients (also called, “nodes”) compliant with the IEEE-802.11-1999 family of standards. A client, when first initialized, must seek a compatible access point with which it may associate in order to pass traffic. Although, according to the standards, traffic is passed on only one channel at a time, a plurality of channels of available wireless spectrum are available for use. Seeking a compatible access point requires a client to tune to each available channel and either actively solicit (sending a “probe”) or passively listen for an identifying transmission (a “beacon”) as described, by way of example and not limitation, in section 7 of the IEEE-802.11-1999 standard. Since the client or an access point might be in motion or subject to environmental or infrastructure changes, a client will periodically search the available channels in order to determine and present the best wireless data connectivity options to a host device.
Low cost, high volume wireless local area network (WLAN) devices are typically equipped with one receiver which must perform both data transfer as well as periodic site surveys. Since, with a single receiver, time spent scanning for channel activity on other than the currently utilized data communications channel requires the client to temporarily suspend data communication with an associated access point (AP), throughput during the scanning time is effectively zero. This “dead time” is especially lengthy in regions wherein the RF regulatory environment prohibits sending a probe, requiring the receiver to dwell on a channel until a beacon is heard or a time limit (typically 100 ms but as much as two seconds) is reached.
There is thus a need in the art for a method and system of efficiently surveying a plurality of available wireless communications channels. There is, further, a need for the method and system to work efficiently in an environment comprised of existing standards-compliant equipment. There is yet a further need felt in office environments implementing WLANS on a plurality of wireless communications channels which would be populated predominantly with enhanced access points for a further improvement in efficiency.